Publications associées à Experimental Investigation of Flow Instabilities and Rotating Stall in a High-Energy Centrifugal Pump Stage

Publications associées (30)

Small-scale turbopumps for waste heat recovery applications based on an organic Rankine cycle: a study from pre-design to experimental validation

The organic Rankine cycle (ORC) system is among the technologies applied to exploit waste heat in vehicles. Since common organic fluids have lower latent heat than water, higher mass flow rates are required to convert the same waste heat, considerably incr ...

EPFL2023

Research data supporting 'Fiber pumps for wearable fluidic systems'

Herbert Shea, Vito Cacucciolo, Michael James Henry Smith

The dataset supporting 'Fiber pumps for wearable fluidic systems', published in Science in March 2023. In this work, we present a fluidic pump in the form of a flexible and stretchable tube. These tubes - or 'fiber pumps' - can generate significant fluidic ...

2023

Design, computational and experimental investigation of a small-scale turbopump for organic Rankine cycle systems

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

The hydraulic design, computational analysis, and experimental investigations of a high-speed small-scale turbopump for mobile waste heat recovery applications based on organic Rankine cycle systems are presented in this paper. Such applications demand hig ...

Elsevier2023

The influence of splitter blades and meridional profiles on the performance of small-scale turbopumps for ORC applications; analysis, neural network modeling and optimization

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

This work presents the influence of splitters on the performance of small-scale turbopumps for organic Rankine cycle applications numerically. Different design parameters, such as impeller diameter at the outlet, number of blades, blade angle at the traili ...

2023

Fiber pumps for wearable fluidic systems

Herbert Shea, Vito Cacucciolo, Michael James Henry Smith

Incorporating pressurized fluidic circuits into textiles can enable muscular support, thermoregulation, and haptic feedback in a convenient wearable form factor. However, conventional rigid pumps, with their associated noise and vibration, are unsuitable f ...

American Association for the Advancement of Science2023

Increasing the Energy Efficiency of Gas Boosters for Hydrogen Storage and for Refueling Stations

Alfred Rufer

A new electrically driven gas booster is described as an alternative to the classical air-driven gas boosters known for their poor energetic efficiency. These boosters are used in small scale Hydrogen storage facilities and in refueling stations for Hydrog ...

MDPI2023

Bioinspired Soft Bendable Peristaltic Pump Exploiting Ballooning for High Volume Throughput

Josephine Anna Eleanor Hughes

Interest in bioinspired peristaltic pumps has grown in popularity among the scientific community in the last decade thanks to their extreme flexibility and their intrinsic compliance. In this paper, we propose a soft peristaltic pump exploiting ballooning. ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

InP/Si3N4 Hybrid External-Cavity Laser with sub-kHz Linewidth Acting as a Pump Source for Kerr Frequency Combs

Tobias Kippenberg, Junqiu Liu

We report on an InP/Si3N4 hybrid integrated ECL that relies on 3D-printed coupling elements such as intra-cavity photonic wire bonds and facet-attached microlenses. We demonstrate 90 nm tuning range, SMSR above 60 dB, and intrinsic linewidths of 979 Hz. We ...

IEEE2022

Numerical Studies of Brillouin-induced Polarization Pulling of Probe and Pump in Weakly-Birefringent Optical fibers with Applications to BOTDA

Luc Thévenaz, Marcelo Alfonso Soto Hernandez

Numerical solution of the involved governing equations confirm that the commonly used two orthogonal sets of gain- and loss-probes in BOTDA, differently affect the evolution of the pump state-of- polarization, thereby potentially compromising the minimizat ...

Optica Publishing Group2022

Techno-economic assessment of postcombustion carbon capture using high-performance nanoporous single-layer graphene membranes

Kumar Varoon Agrawal, Mostapha Dakhchoune, Marina Micari

High-performance membranes have emerged as an energy-efficient alternative to absorption-based postcombustion carbon capture. So far, the techno-economic analyses have been centered around the polymeric membranes. Recently, nanoporous single-layer graphene ...

2021

Numerical investigation on the volute cutwater for pumps running in turbine mode

Elena Vagnoni, Alessandro Morabito

The hydropower sector has recently raised the interest in pump as turbine (PaT) that can be a valid trade-off between capital cost and performance in micro-scale installations. Nevertheless, the modest efficiency of PaTs often restricts their exploitation. ...

Pergamon-Elsevier Science Ltd2021

An experimental study on the upper part-load elliptical vortex instability in a Francis turbine

François Avellan, Elena Vagnoni, Andres Müller, Arthur Tristan Favrel, Ali Amini

This paper presents preliminary results of an experimental study on the occurrence and development of the upper part-load instability in a reduced-scale Francis turbine. The study includes draft tube pressure measurements, high-speed flow visualization, an ...

IOP Publishing2021

Scale limitations of gas bearing supported turbocompressors for vapor compression cycles

Jürg Alexander Schiffmann

An analysis of single-stage centrifugal compressors supported on dynamic, gas lubricated bearings for driving vapor compression cycles suggests that the maximum feasible compressor power is limited, primarily by the bearing load capacity, in the range from ...

2020

Electrically-Driven Soft Fluidic Actuators Combining Stretchable Pumps With Thin McKibben Muscles

Herbert Shea, Vito Cacucciolo

Soft wearable robots could provide support for lower and upper limbs, increase weight lifting ability, decrease energy required for walking and running, and even provide haptic feedback. However, to date most of wearable robots are based on electromagnetic ...

2020

Physical Mechanism and Flow Control of Tip Vortex Cavitation

Ali Amini

Occurrence of cavitation in hydraulic machines is a challenging issue because it is often accompanied with loss of efficiency, noise emissions, vibrations, and erosion damages. Tip vortices, in particular, are an ideal site for the development of cavitatio ...

EPFL2020

Autonomous oil flow generated by self-oscillating polymer gels

Vito Cacucciolo

The previously reported gel and polymer actuators require external inputs, such as batteries, circuits, electronic circuits, etc., compared with autonomous motions produced by the living organisms. To realize the spontaneous motions, here, we propose to in ...

Nature Research2020

Advanced design methods and non-ideal gas lubrication applied to aerodynamic bearings

Eliott Philippe Guenat

Clean and energy-efficient turbomachinery are playing an increasingly important role in the decarbonization of heating systems, waste heat recovery and transportation, as the use of small-scale heat pumping and fuel cells spreads. Such machines typically e ...

EPFL2020

Unsteady Flow Numerical Simulations on Internal Energy Dissipation for a Low-Head Centrifugal Pump at Part-Load Operating Conditions

François Avellan, Xiaoran Zhao

Dredge pumps are usually operated at part-load conditions, in which the low-solidity centrifugal impeller could experience large internal energy dissipation, related to flow separation and vortices. In this study, SST k- and SAS-SST turbulence models were ...

2019

Mitigation of tip leakage induced phenomena in a low Reynolds number centrifugal compressor via blade loading distribution

Markus Diehl

Reduced-scale refrigeration compressors supported on gas-lubricated bearings have been identified as a key technology for domestic heat pump applications, in order to improve both the system efficiency and the reliability. Unfortunately, reduced-scale mach ...

EPFL2019

Oxygen diffusion through air–water free surfaces in a pump–turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto

The present research aims at understanding the mass transfer of air into water in a reversible pump turbine operating in condenser mode. In particular, the diffusion of oxygen through the water free-surface both in the vaneless gap between the impeller bla ...

2019